The advent of the Internet and improvements in computer technology have lead to more frequent transmission of color image data via computer networks and to the display of color images on computers or like devices. It is expected that the use of computers for displaying color image data and the need to enhance image quality will continue to increase, particularly as computers and like devices are used to display motion pictures.
Various filter and image data processing circuits/logic have been developed to support advances in digital color image data processing. These circuits/logic include color, contrast, brightness and related circuits/logic.
Color image data is typically generated by subjecting raw image data to a compression algorithm. The compressed data can be more rapidly transmitted and/or more efficiently stored than non-compressed data. The compressed data is decompressed and interpolated for display.
During compression (and due to other causes), defects may be introduced into color image data. These defects often take the form of holes or graininess in a displayed image. Decompression and interpolation algorithms may also contribute to these defects.
In an effort to reduce image defects and to generally improve image quality, color filter circuits/logic have been developed. In a parallel filtering arrangement, separate filters operate on each of the three primary color signals. This results in rapid processing, but necessitates a large amount of processing circuitry. In a serial filtering arrangement, each color signal is fed serially through the same filter circuitry. While serial arrangements decrease the requisite amount of circuitry by approximately two-thirds compared to parallel arrangements, serial arrangements increase processing time approximately three-fold.
In addition to noise and defect reduction, filters also reduce the clarity or sharpness of an image. Thus, by filtering each of the color signals, a cumulative reduction in image clarity is produced.